Building Maintenance Units (BMUs) are used to maintain or repair the structure of high-rise buildings.

In Australia, they are classed as either Type A or Type B.

Type A BMUs are required on buildings over 40 metres in height from the lowest point, and they have the motors and wire rope drums located on the roof in the ‘roof car’ component of the BMU. The façade also will require BMU restraint pins located on the façade to restrain BMU wire ropes and prevent the extent the cradle can be blown off the façade.

Building Maintenance Unit


Type B BMUs are suitable for building heights less than 40 metres, the motors are typically located in the cradle, and no facade restraints are required.

Building Maintenance Unit

Long gone are the days of square or rectangular skyscrapers. Now we have beautiful glass curves, elegant steel spires and vertical vegetation all enhancing our urban environment. The more imaginative and decorative facades create a challenge for the manufactures of BMUs. The teams of designers, engineers and tradespersons who build the BMUs revel in these challenges, and as a result, we have seen enormous improvements in BMU design, functionality and safety.

A year ago, XSPlatforms in the Netherlands opened their own office in Australia, with staff based in Melbourne and Sydney. In that time they have delivered five BMU systems to new buildings and one to a building refurbishment. The company is currently building the world’s largest BMU for an amazing façade at the National Bank of Kuwait, with the amazing work shown in the video below:

Each BMU should not only be designed for perfect functionality and safety, but also with an eye to beautiful architecture. The starting point when considering a BMU should be the client’s requirements and I would recommend engaging a façade access consultant. It’s a very specialised field, but we are lucky in Australia to now have a handful of very competent consultants that can advise you.

Some things to consider when selecting a BMU:

  • Before going to market, get professional advice and produce a detailed scope of works
  • BMUs are strongly recommended for all heights over 40 metres
  • Consider the work typically carried out on the façade and its impact on cradle load capacity and frequency of use
  • Consider the complexity of the façade and its effect on the BMU design and the building design
  • Look at the experience of the BMU supplier and their capacity for manufacture and installation before hiring them on
  • Determine what service spares and support is available
  • Learn what reference projects the BMU provider can offer
  • Look into the safety record of the BMU provider; ask about accidents with their equipment
  • Ask what remote maintenance functions the BMU provider can offer to detect malfunctions by looking at BMU data remotely

Conversation around BMUs must be centred around safety. Ensure the design provides the safest outcome for the user and those around the BMU. Then you should look at functionality, ease of use and finally integration into your building.